The present invention relates generally to endoscopic surgical equipment and more specifically to infusion sleeves used in phacoemulsification.
Phacoemulsification involves emulsifying the natural lens in situ using an ultrasonically vibrating hollow needle. The emulsified lens is aspirated out of the eye through the hollow needle simultaneously with the infusion of a saline solution. The saline solution is generally infused through the space between the outside of the needle and a thin, flexible sleeve that is held coaxial with the needle. One of the primary benefits of phacoemulsification is that the lens can be removed through a very small incision. With the recent introduction of foldable intraocular lenses, and the ability to insert these replacement lenses through even smaller incisions, the desirable size of the incision through which the phacoemulsification tip and irrigating sleeve must pass is also becoming smaller.
While the desirable phacoemulsification incision size has become smaller, the overall diameter of the cutting tip/sleeve combination has remained relatively constant. As a result, the tip/sleeve combination must be used in a very tight wound. While the elasticity of the eye tissue allows some manipulation of the tip/sleeve within the wound, this tight wound structure holds the sleeve tightly, and prevents the tip from being rotated within the wound. While rotation of the tip is not as important for square cut tips, tips that have been cut on a bevel or that contain a slight bend at the distal end often must be rotated within the eye to take full advantage of the design of the particular tip.
Accordingly, a need continues to exist for an infusion sleeve that permits the cutting tip to be rotated within tight wounds and for a sleeve that reduces excess infusate flow out of the wound, thus allowing for more precise fluidic balance and control.